Peters



s sheets-'sheep' 1.

(No Model.) Y Y ApJ. MARTIN.

vCHANGEABLE SPEED G-rEAIRINGl` No.-saow1.53o.A PatentedJune 7,1887.

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3 Sheets-Sheet 2.

(No Model.)

A. J. MARTIN.

GHANGEABLE SPEED' GBARING.

No. 364.530. Patented June- 7, I1887.

,J1/ll i N. PETERS, Pmwmhagnpur, wauhmgmn u.' i:

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A. J. MARTIN. metnmrmmav SPEED GBARING.

Patented June 7 yNo. 364,530.

N.- PETERS. Puma-umm, wmmmri. u. C.

UNITED STATES PATENT OFFICE.

ANDREW J. MARTIN, OF MACEDON, NFNV YORK.

CHANGEABLE-SPEED GEARING.

SPECIFICATION forming part of Letters Patent No. 364,530, dated June 7,1887.

' Application filed December 4, 1886. Serial No. 120,672. (No model.)

.To au whom it' may concern:

Be it known that I, ANDREW J. MARTIN, of Macedon, in the county of Wayneand State of New York, have invented certain Improvements inOhangeableSpeed Gearing, of which the following is a specification.

My invention relates to an improved mechanism whereby a crank or cranksrevolving at a uniform speed may impart to a driven shaft a faster orslower motion, as demanded, the speed of the driven shaft being variableby imperceptible degrees between the eXtreme limits. Y

To this end the invention relates to the combination of acrank or cranksof variable throw with toggle-joints, and dogs or clutches carried bysaid joints and acting to revolve a wheel with which they engage, ashereinafter l Fig. 2 isa side elevation of the same.

more fully explained.

Referring to the accompanying drawings, Figurel represents a top planview of a mechanism in which m invention is embodied. Fig. 3 is across-section on the line x gr, Figsl and 2. Fig. 4L is a sideelevation,with parts shown in vertical section on the line y y, Fig. 5,showing one of the dogs `or clutches. Fig. 5 is a cross-section on theline z z of the preceding iigure. Fig. 6 is an outline view ofamodification.

Referring tol the drawings, A represents a substantial fran1e,which maybe of any suitable form and construction,adapted to support theoperative parts hereinafter described. B is a horizontal driving-shaftmounted in bearings on the frame, and provided with a drivingpulley, C,or other driving device,constituting the prime mover of my mechanism.'Io opposite ends of the shaft B are secured rigidly two wheels, D D',each provided with a radial slot, a, containing a movable crankpin,E,the inner end of which is attached to or formed into a slide adapted toengage suitable guides on the inner face of the wheel, this constructionpermitting the crank-pin to be moved to and from the center in order tovary the extent of its throw. Means of any suitable character maybe usedfor adjusting the crank-pin, but I prefer the means which will behereinafter described in detail. From the respective crank-pins I extendpitmen F F' to opposite "horizontal guides II and H'.

ends of the frame, where they are connected, respectively, to slides Gand G', working in At a suitable distance from these slides I mount,parallel with the driviugshaft B, a driven shaft, K, having fixed onopposite ends the wheels L and L', each having in its outer face acircular groove, M, concentric with the shaft.

On one end of the shaft K, I journal loosely two toggle-j oints,I and.Lwhich have their opposite ends pivoted or journaled to the slide G,the parts being so arranged that when the slide is moved to and fro thetwo toggles will be flexed or bent in opposite directionsone upward andthe other downward. To each'of these toggles I attach a friction-dogengaging the wheel L, and both tending when in action to turn it in onedirection. The construction of these dogs is shown in Figsfi and 5,inwhich Nrepresents a divided friction-block seated in the groove M of thewheel and recessed` at the middle to receive an angular stud, O,`xed onthe arm I), which latter is pivoted at its outer end to one `of themembers of the toggle. A spring, R, attached to the toggle bears on theblock N and tends to urge the same endwise in the groove. Vhen the armof the toggle is moved forward, as indicated by the dotted arrow in Fig.4, it carries forward the upper end of the arm I?, causing the restOonits inner end to separate the two parts of the block N and force themagainst opposite walls of the groove M. This action causes the blocks toengage with such rmness that the wheel is compelled to turn forward withthe toggle and the arm P. When the motion of the toggle is reversed, theupper end of the arm P is turned. rearward, and its rest O caused torelieve the block M from the internal pressure, so that it may slidefreely backward in the groove under the influence of the spring It.` Thedevices thus arranged form a friction dog or clamp which is noiselessinits action, and which acts instantly to lock the wheel to the toggleas the latter commences its forward motion.

Owing to the fact that the toggles I and J move in opposite directions,the dog of one will urge the wheel forward while the dog of the other isretreating, and thus it is that the two dogs acting alternately impartto the wheel a constant rot-ation.

ICO

On the opposite side of the machine I conneet with the slide Gva secondpair of toggles,

I and J, provided with dogs to engage the wheel L, these parts beingduplicates of those before described.

The crank-pins E and E, through which the toggle mechanism on oppositesides of the ma chine receive motion,are setquarterl y-that 1S to say,on radial lines standing atan angle of ninetydegrees to each other, orthereabout. The effect of this arrangement is to operate the toggles andclutches on opposite sides of the machine atsuch times, orin suchrelations to each other, that a practically constant rate of speed isimparted through the wheels L to the shaft K during its revolution. Itis mania fest that the crank, pitman, and toggle connections on one sideof the machine could be omitted;but in such case the speed of the shaftK would vary greatly during each revolution. For many purposes it isnecessary that the driven shaft should receive a practically constantspeed during its entire revolution, and this is secured bythe employmentof the four toggles and clutches operatin g in the described relations.i

By changing the throw of the crank-pins E and E the length of the aresthrough which the toggles vibrate may be increased or diminished, and inthis manner the speed of the shaft K may be increased or diminished atwill with reference to the speed of the drivingshaft B.

It will be observed, as a peculiarity of my organizatiomthat thisadjustment may be made gradually or by imperceptible degrees, and thusthe speed of the driven shaft regulated with great nicety.

a For the purpose of adjusting the crank-pins simultaneously andequally, I recommend the construction represented in Figs. 2 and 3, inwhichitwill be perceived that the driving-shaft B is made of tubularform from end to end to receive a central shaft, c, bearing at its endspinions d, which engage rack-bars c, attached to the respectivecrank-pins, as shown in dotted lines in Fig. 2. The rotation of thecentral shaft within the main shaft will therefore adjust the twocrank-pinsinward or outward and maintain them at equal distances fromthe center. As a means of turning this shaft and indicating theadjustment of the crank-pins, I attach to one end of the shaft C an armor binder, b, arranged to traverse the outer face of the wheel D, whichwill be provided with suitable marks or graduations. 'When the speed ofthe driving-shaft is known, these graduations may be used to indicate,in connection with the pointer, the exact speed of the driven shaft. Asa means for securing the pinion and crank-pins, I provide one end of thecentral shaft, c, with a nut, f, by which' the shaft may be drawnendwise and the parts clamped tightly together to prevent the rotationof the pinions.

Instead of the sliding crankpins above described, I may employcrank-pins mounted on swinging plates 7c, pivoted tothe crank-wheels andprovided with a sector-rack. engaging adjnstiiigpinions, which will bemounted on the central shaft, as explained.

In the drawings I have shown the clutchwheel L provided with peripheralgear-teeth S, which impart motion, through a pinion, T, to a shaft, n,whence the motion may be cornmunicated to any desired point; but it isto be understood that this shaft and pinion may be omitted and motiontransmitted in any other suitable manner from the shaft K.

The essence of my invention lies in combining with a driven wheel, as L,a toggle having a dog to turn said wheel, and a crank adjustable as toits th rowfor operating said dog, and` it is manifest that the detailsof construction may be variously modified by the skilled mechanicwithout departing from the limits of the invention.

My mechanism is adapted for application to steam -engines, grain-drills,grinding-machines, and generally to all structures in which a primemover having a constant speed is required to transmit variablespeeds toa driven shaft.

I am aware that toggle-joints provided with pawls have been combinedwith a ratchetwheel driven by the pawls, and to such com-v bination,broadly considered, I lay no claim.

If desired, the tightening-nut and the indicator-hand may be placed atone and the same end of the central shaft, and, where circum-v stancesadmit of its being done, the nut may be replaced by any equivalent meansof securing the central shaft against rotation.

Having thus described my invention, what I claim is l. The drivingshaftand its two wheels having their crank-pins out of line, the pitmen, thetwo slides actuated thereby, the shaft K and its wheels L, the fourtoggle-joints, eon nected, two to each slide, and thefriction-clampsconnecting the respective togglejoints with the wheels L, substantiallyas described,where by a continuous and practically uniform motion may becommunicated from the drivingshaft to the shaft K.

2. In a mechanism for imparting a variable rotary motion from a crankhaving a constant revolving speed, the combination of a drivingcrankadjustable as to the length of its throw, a pitman connected thereto, aslide connected to and actuated by the pitman, a wheel, L, and twooppositely-arranged toggle-joints con nected to the slide and providedwith dogs acting alternately to turn the wheel L in one and the samedirection. v

3. In combination with the wheel L, a toggie provided with a dog to turnthe wheel, a pitman to actuate the toggle, the driving-wheel providedwith the tubular shaft and radiallymovable crank-pin, and the centralshaft provided with the pinion to adjust the crank-pin.

4. In combination with the tubular drivingshaft and the slotted wheelsfixed thereon, the sliding crank-pins provided with racks and the may beincreased or diminished without the,

i 5 speed of the driving-crank.

7 Two cranks arranged at an angle of ninety degrees, or thereabout, toeach other, in combination with the four toggle-joints operated two byeach crank, dogs attached to the tog-- t gie-joints and ail acting inone direction, and zo a shaft, K, provided with xed wheels actuatedbythe dogs, whereby a constant and practically uniform motion may bccommunicated to said shaft during its entire revolution'.

In testimony whereof I hereunto s et my 25 hand, this 25th day ofOctober, 1886, 1n the presence of two attesting witnesses.

ANDREW J. MARTIN. l

Witnesses:

GEo. NoXoN, DEWITT C. BRUNDAGE.

